Piezoelectric/electrostrictive devices such as actuator devices, sensor devices, etc. using piezoelectric/electrostrictive layers are produced by forming an interconnection pattern comprising an electrode layer on a ceramic base as by printing, forming a piezoelectric/electrostrictive layer on the interconnection pattern by printing, thereafter baking the assembly to secure the layers, and then forming an interconnection pattern comprising another electrode layer (see, for example, Japanese laid-open patent publication No. 2001-320103,.
The piezoelectric/electrostrictive device may be used as an actuator device wherein an electric signal is supplied to the interconnection patterns to apply an electric field to the piezoelectric/electrostrictive layer for thereby displacing the piezoelectric/electrostrictive layer. The piezoelectric/electrostrictive device may also be used as a sensor device wherein an electric signal generated depending on a pressure applied to the piezoelectric/electrostrictive layer is extracted from the interconnection patterns.
The present applicant has proposed a piezoelectric/electrostrictive device which has a longer service life and an improved handling capability, allows a component to be more easily attached to its movable portion, and can be fixed in place with greater ease (see, for example, publication EP1089357A2). The proposed piezoelectric/electrostrictive device permits the movable portion to be displaced greatly with a relatively low voltage, and the device, particularly the movable portion, can be displaced at a higher speed (at a higher resonant frequency). In addition, the piezoelectric/electrostrictive device can provide a displacement device which is less susceptible to harmful vibrations, can respond at a high speed, has high mechanical strength, can be handled with ease, and has excellent shock resistance and humidity resistance, and can also provide a sensor device which is capable of detecting vibrations of the movable portion with accuracy.
As shown in FIG. 18 of the accompanying drawings, the piezoelectric/electrostrictive device 200 employs a highly flowable adhesive as an adhesive 208 used to bond thin plates 206a, 206b to a fixing member 202 and an article 204. Particularly, the thin plates 206a, 206b have protrusions 210 for defining regions where the adhesive 208 is provided. When the thin plates 206a, 206b are to be bonded to the fixing member 202 and the article 204 by the adhesive 208, the protrusions 210 define regions where the adhesive 208 is provided.
It is an object of the present invention to provide a method of manufacturing a high-performance piezoelectric/electrostrictive device having thin plates of ceramics and protrusions whose shape does not tend to affect the mechanical characteristics of the thin plates by optimizing a process of forming the protrusions and the shape of the protrusions.